| Zinc alloy has a good application prospect in the field of biodegradation and bioactivity materials for tissue repairing and tissue engineering for its strength and biocompatibility.But it has some problems such as suddenly emitting vastly greater amounts of zinc in the early days of grafting and biocompatibility.HA+?-TCP biphasic calcium phosphate bio-ceramic is a kind of biomedical porous ceramic material which has the ability of good degradability,osteoinduction and biological compatibility.A kind of compound material constituted by HA+?-TCP+MgO biphasic calcium phosphate bio-ceramic and zinc alloy was prepared in this paper to improve the degradation behavior and biocompatibility of zinc alloy.Firstly,the method of polymeric foam replication was used for the preparation of HA+?-TCP+MgO.The effects of the amount of MgO powder on the compression strength and structure of?-TCP bio-ceramic were studied to determine the best amount of MgO powder.Secondly,HA+?-TCP+MgO biomedical porous ceramic was prepared according to the best amount of MgO powder in the previous step.Thirdly,Zn,Zn-Mg and Zn-3Sn base composite materials were prepared by the use of vacuum infiltration method.Scanning electron microscopy?SEM?with energy spectrometer,X-ray diffract meter?XRD?,material universal testing machine,electrochemical workstation and the SBF test were used to study the phase composition,microstructure,mechanical properties and the degradation performance of biphasic calcium phosphate bio-ceramic and zinc alloy base composite materials.The results showed that the shape integrity of MgO+?-TCP porous bio-ceramics increased to the maximum and then decreased with the contents of MgO.And it increased to the maximum when the contents of MgO reached 1wt.%.The compression performance of 1MgO+?-TCP porous bio-ceramics was the best.The shape integrity of HA+?-TCP+MgO porous bio-ceramics increased to the maximum and then decreased with increasing of the contents of HA.And it was best when the content of HA reached 50wt.%.The interface bond integrity of?MgO+?-TCP?/Zn-Mg composites was good and the mechanical properties of them reached the best when the contents of MgO reached 1wt.%.The interfacial bond integrity of?HA+?-TCP+MgO?/Zn-Mg composites increased to the maximum and then decreased with increasing of the contents of HA.And it increased to the maximum when the contents of HA reached 30wt.%.And the mechanical properties reached 189±27 MPa,the best in this composition.The interfacial bond integrity of?HA+?-TCP+MgO?/Zn composites and?HA+?-TCP+MgO?/Zn-3Sn composites was good.The shape integrity and the mechanical properties of them increased with the contents of HA.The largest compression strength of them were 175±28MPa and 105±30 MPa,respectively.The compressive stresses meet the requirements of hard tissue implants.The rates of degradation of zinc based composites were faster than zinc based alloy.The rates of degradation of Zn-Mg base composites with the contents of HA ranged from 10wt.%to30wt.%were slower than those of HA more than 50wt.%.The corrosion resistance decreased with the contents of HA in zinc based composites and Zn-3Sn based composites.The rates of degradation of four compositions of composites were low.The content of Zn2+ion in soak liquid of SBF after 15 days of immersion test was lower than 6mg/L.The result showed that the composites were not toxic in the human body.The pH is between 6.8 and 7.8 during the immersion test,which showed that the four compositions of composites were stable in chemical properties in the human body. |
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